Hampshire

Introduction

Hampshire occupies the northern part of a broad syncline that runs from west to east through The Solent and Spithead. The Chalk of the Dorset Downs and Salisbury Plain subsides beneath Tertiary formations comprising the Bagshot Beds (Poole Formation), overlain by the Lower Oligocene Barton and Bracklesham Beds and the Upper Oligocene Hamstead and Bembridge Beds: a succession of sands, clays, marls and some limestones. In Late Tertiary times the so-called Solent River was an eastward extension of the Dorset Frome eastward through a valley which ran along the syncline, and the geological formations are sequences of marine, estuarine, deltaic and valley floor deposits that formed as sea level rose and fell (marine transgressions and regressions) along this valley (Everard 1954). The southern side of the valley was for long the Chalk ridge of the Purbeck Hills extending eastward through the centre of the Isle of Wight. This was breached by marine erosion to form the 24 km...